Experimental and kinetic study of vacuum residue cracking over zirconium based catalysts

Abstract

In this study, thermal cracking and catalytic cracking over zirconium-based catalysts of the vacuum residue were achieved in the presence of supercritical steam at 400-450 degrees C, 20 bar, and 2-4 h. Two different catalysts (ZrFeNi and ZrCoNi) were prepared using a sol-gel precipitation method and characterized using X-ray diffraction, EDX-spectrum, scanning electron microscopy, and BET surface area. The results showed the lowest VR conversion was achieved in the thermal cracking, catalytic cracking using ZrFeNi and catalytic cracking using ZrCoNi were 31.7, 35.3, and 38% while the highest VR conversion was achieved in the thermal cracking, catalytic cracking using ZrFeNi and catalytic cracking using ZrCoNi were 38.6, 71.1 and 76.3%. A new kinetic model of the eight lumps and 28 reaction steps were developed to describe the VR cracking while a genetic algorithm optimization method was used to predict the optimum set of kinetic parameters in which all computations were achieved using MATLAB version 2020a.